The tragedy of the commons is a situation in a shared-resource system where individual users, acting independently according to their own self-interest, behave contrary to the common good of all users by depleting or spoiling the shared resource through their collective action. The theory originated in an essay written in 1833 by the British economist William Forster Lloyd, who used a hypothetical example of the effects of unregulated grazing on common land (also known as a "common") in Great Britain and Ireland.[1] The concept became widely known as the "tragedy of the commons" over a century later due to an article written by American biologist and philosopher Garrett Hardin in 1968.[2] In this modern economic context, "commons" is taken to mean any shared and unregulated resource such as atmosphere, oceans, rivers, fish stocks, roads and highways, or even an office refrigerator.

Although common resource systems have been known to collapse due to overuse (such as in over-fishing), many examples have existed and still do exist where members of a community with access to a common resource co-operate or regulate to exploit those resources prudently without collapse.[3][4]Elinor Ostrom was awarded the 2009 Nobel Prize in Economics for demonstrating exactly this concept in her book Governing the Commons, which included examples of how local communities were able to do this without top-down regulations or privatization.[5]

Expositions

Lloyd's pamphlet

In 1833, the English economist William Forster Lloyd published a pamphlet which included a hypothetical example of over-use of a common resource. This was the situation of cattle herders sharing a common parcel of land on which they were each entitled to let their cows graze, as was the custom in English villages. He postulated that if a herder put more than his allotted number of cattle on the common, overgrazing could result. For each additional animal, a herder could receive additional benefits, while the whole group shared the resulting damage to the commons. If all herders made this individually rational economic decision, the common could be depleted or even destroyed, to the detriment of all.[1]

Hardin discussed problems that cannot be solved by technical means, as distinct from those with solutions that require "a change only in the techniques of the natural sciences, demanding little or nothing in the way of change in human values or ideas of morality". Hardin focused on human population growth, the use of the Earth's natural resources, and the welfare state.[6] Hardin argued that if individuals relied on themselves alone, and not on the relationship of society and man, then the number of children had by each family would not be of public concern. Parents breeding excessively would leave fewer descendants because they would be unable to provide for each child adequately. Such negative feedback is found in the animal kingdom.[6] Hardin said that if the children of improvident parents starved to death, if overbreeding was its own punishment, then there would be no public interest in controlling the breeding of families.[6] Hardin blamed the welfare state for allowing the tragedy of the commons; where the state provides for children and supports overbreeding as a fundamental human right, Malthusian catastrophe is inevitable. Consequently, in his article, Hardin lamented the following proposal from the United Nations:

The Universal Declaration of Human Rights describes the family as the natural and fundamental unit of society. [Article 16] [7] It follows that any choice and decision with regard to the size of the family must irrevocably rest with the family itself, and cannot be made by anyone else.

In addition, Hardin also pointed out the problem of individuals acting in rational self-interest by claiming that if all members in a group used common resources for their own gain and with no regard for others, all resources would still eventually be depleted. Overall, Hardin argued against relying on conscience as a means of policing commons, suggesting that this favors selfish individuals– often known as free riders– over those who are more altruistic.

In the context of avoiding over-exploitation of common resources, Hardin concluded by restating Hegel's maxim (which was quoted by Engels), "freedom is the recognition of necessity". He suggested that "freedom" completes the tragedy of the commons. By recognizing resources as commons in the first place, and by recognizing that, as such, they require management, Hardin believed that humans "can preserve and nurture other and more precious freedoms".

The "Commons" as a modern resource concept

Hardin's article was the start of the modern use of "Commons" as a term connoting a shared resource. As Frank van Laerhoven and Elinor Ostrom have stated: "Prior to the publication of Hardin’s article on the tragedy of the commons (1968), titles containing the words 'the commons', 'common pool resources,' or 'common property' were very rare in the academic literature." They go on to say: "In 2002, Barrett and Mabry conducted a major survey of biologists to determine which publications in the twentieth century had become classic books or benchmark publications in biology. They report that Hardin’s 1968 article was the one having the greatest career impact on biologists and is the most frequently cited".[9]

Application

Metaphoric meaning

Like Lloyd and Thomas Malthus before him, Hardin was primarily interested in the problem of human population growth. But in his essay, he also focused on the use of larger (though finite) resources such as the Earth's atmosphere and oceans, as well as pointing out the "negative commons" of pollution (i.e., instead of dealing with the deliberate privatization of a positive resource, a "negative commons" deals with the deliberate commonization of a negative cost, pollution).

As a metaphor, the tragedy of the commons should not be taken too literally. The "tragedy" is not in the word's conventional or theatric sense, nor a condemnation of the processes that lead to it. Similarly, Hardin's use of "commons" has frequently been misunderstood, leading him to later remark that he should have titled his work "The Tragedy of the Unregulated Commons".[10][11]

The metaphor illustrates the argument that free access and unrestricted demand for a finite resource ultimately reduces the resource through over-exploitation, temporarily or permanently. This occurs because the benefits of exploitation accrue to individuals or groups, each of whom is motivated to maximize use of the resource to the point in which they become reliant on it, while the costs of the exploitation are borne by all those to whom the resource is available (which may be a wider class of individuals than those who are exploiting it). This, in turn, causes demand for the resource to increase, which causes the problem to snowball until the resource collapses (even if it retains a capacity to recover). The rate at which depletion of the resource is realized depends primarily on three factors: the number of users wanting to consume the common in question, the consumptive nature of their uses, and the relative robustness of the common.[12]

The same concept is sometimes called the "tragedy of the fishers", because fishing too many fish before or during breeding could cause stocks to plummet.[13]

Modern commons

The tragedy of the commons can be considered in relation to environmental issues such as sustainability. The commons dilemma stands as a model for a great variety of resource problems in society today, such as water, forests,[14] fish, and non-renewable energy sources such as oil and coal.

Situations exemplifying the "tragedy of the commons" include the overfishing and destruction of the Grand Banks, the destruction of salmon runs on rivers that have been dammed – most prominently in modern times on the Columbia River in the Northwest United States, and historically in North Atlantic rivers – the devastation of the sturgeon fishery – in modern Russia, but historically in the United States as well – and, in terms of water supply, the limited water available in arid regions (e.g., the area of the Aral Sea) and the Los Angeles water system supply, especially at Mono Lake and Owens Lake.

In economics, an externality is a cost or benefit that affects a party who did not choose to incur that cost or benefit. Negative externalities are a well-known feature of the "tragedy of the commons". For example, driving cars has many negative externalities; these include pollution, carbon emissions, and traffic accidents. Every time 'Person A' gets in a car, it becomes more likely that 'Person Z'– and millions of others– will suffer in each of those areas.[15] Economists often urge the government to adopt policies that "internalize" an externality.[16]

The tragedy of commons can also be referred to the idea of open data. Scholars have misinterpreted the literature on computer science and statistics, thus clearly exaggerating the futility of anonymising data. Further, the risks posed by anonymised data are theoretical in nature they rarely occur. Finally, anonymised data are crucial for useful social research and represent therefore a public resource – better said a common good – which is liable to exhaustion. In conclusion, some feel that the law should provide a safe haven for the dissemination of research data, since it can be argued that current data protection policies overburden valuable research without mitigating realistic risks.[17]

Examples

More general examples (some alluded to by Hardin) of potential and actual tragedies include:

Light pollution– with the loss of the night sky for research and cultural significance, affected human, flora and fauna health, nuisance, trespass and the loss of enjoyment or function of private property.[18]

Antibiotics–Antibiotic Resistance Mis-use of antibiotics anywhere in the world will eventually result in antibiotic resistance developing at an accelerated rate. The resulting antibiotic resistance has spread (and will likely continue to do so in the future) to other bacteria and other regions, hurting or destroying the Antibiotic Commons that is shared on a worldwide basis[24]

Vaccines–Herd immunity Avoiding a vaccine shot and relying on the established herd immunity instead will avoid potential vaccine risks, but if everyone does this, it will diminish herd immunity and bring risk to individuals that cannot receive vaccines for medical reasons.[25]

Publicly shared resources

Spam email degrades the usefulness of the email system and increases the cost for all users of the Internet while providing a benefit to only a tiny number of individuals.

Skills acquisition and training, when all parties involved pass the buck on implementing it.[27]

Electric vehicle (EV) charging station blocked by parked vehicles, ICE vehicles whose drivers resent EVs, EVs that overstay time limits, and EVs whose owners have no intention of charging but feel they are entitled to park.

Space debris in Earth's surrounding space leading to limited locations for new satellites and the obstruction of universal observations.[28]

Application to evolutionary biology

A parallel was drawn recently between the tragedy of the commons and the competing behaviour of parasites that through acting selfishly eventually diminish or destroy their common host.[29] The idea has also been applied to areas such as the evolution of virulence or sexual conflict, where males may fatally harm females when competing for matings.[30] It is also raised as a question in studies of social insects, where scientists wish to understand why insect workers do not undermine the "common good" by laying eggs of their own and causing a breakdown of the society[citation needed].

The idea of evolutionary suicide, where adaptation at the level of the individual causes the whole species or population to be driven extinct, can be seen as an extreme form of an evolutionary tragedy of the commons.[31][32] From an evolutionary point of view, the creation of the tragedy of the commons in pathogenic microbes may provide us with advanced therapeutic methods.[33][bettersourceneeded]

Commons dilemma

The commons dilemma is a specific class of social dilemma in which people's short-term selfish interests are at odds with long-term group interests and the common good.[34] In academia, a range of related terminology has also been used as shorthand for the theory or aspects of it, including resource dilemma, take-some dilemma, and common pool resource.

Commons dilemma researchers have studied conditions under which groups and communities are likely to under- or over-harvest common resources in both the laboratory and field. Research programs have concentrated on a number of motivational, strategic, and structural factors that might be conducive to management of commons.

In game theory, which constructs mathematical models for individuals' behavior in strategic situations, the corresponding "game", developed by Hardin, is known as the Commonize Costs– Privatize Profits Game (CC–PP game).

Psychological factors

Kopelman, Weber, & Messick (2002), in a review of the experimental research on cooperation in commons dilemmas, identify nine classes of independent variables that influence cooperation in commons dilemmas: social motives, gender, payoff structure, uncertainty, power and status, group size, communication, causes, and frames. They organize these classes and distinguish between psychological individual differences (stable personality traits) and situational factors (the environment). Situational factors include both the task (social and decision structure) and the perception of the task.[35]

Empirical findings support the theoretical argument that the cultural group is a critical factor that needs to be studied in the context of situational variables.[36][full citation needed] Rather than behaving in line with economic incentives, people are likely to approach the decision to cooperate with an appropriateness framework.[37] An expanded, four factor model of the Logic of Appropriateness,[38][39][full citation needed] suggests that the cooperation is better explained by the question: "What does a person like me (identity) do (rules) in a situation like this (recognition) given this culture (group)?"

Strategic factors

Strategic factors also matter in commons dilemmas. One often-studied strategic factor is the order in which people take harvests from the resource. In simultaneous play, all people harvest at the same time, whereas in sequential play people harvest from the pool according to a predetermined sequence– first, second, third, etc. There is a clear order effect in the latter games: the harvests of those who come first– the leaders– are higher than the harvest of those coming later– the followers. The interpretation of this effect is that the first players feel entitled to take more. With sequential play, individuals adopt a first come-first served rule, whereas with simultaneous play people may adopt an equality rule. Another strategic factor is the ability to build up reputations. Research [by whom?] found that people take less from the common pool in public situations than in anonymous private situations. Moreover, those who harvest less gain greater prestige and influence within their group.

Structural factors

Hardin stated in his analysis of the tragedy of the commons that "Freedom in a commons brings ruin to all."[40] One of the proposed solutions is to appoint a leader to regulate access to the common. Groups are more likely to endorse a leader when a common resource is being depleted and when managing a common resource is perceived as a difficult task. Groups prefer leaders who are elected, democratic, and prototypical of the group, and these leader types are more successful in enforcing cooperation. A general aversion to autocratic leadership exists, although it may be an effective solution, possibly because of the fear of power abuse and corruption.

The provision of rewards and punishments may also be effective in preserving common resources. Selective punishments for overuse can be effective in promoting domestic water and energy conservation– for example, through installing water and electricity meters in houses. Selective rewards work, provided that they are open to everyone. An experimental carpool lane in the Netherlands failed because car commuters did not feel they were able to organize a carpool.[41] The rewards do not have to be tangible. In Canada, utilities considered putting "smiley faces" on electricity bills of customers below the average consumption of that customer's neighborhood.[42]

Solutions

Articulating solutions to the tragedy of the commons is one of the main problems of political philosophy. In many situations, locals implement (often complex) social schemes that work well. The best governmental solution may be to do nothing. When these fail, there are many possible governmental solutions such as privatization, internalizing the externalities, and regulation.

Non-governmental solution

Sometimes the best governmental solution may be to do nothing. Robert Axelrod contends that even self-interested individuals will often find ways to cooperate, because collective restraint serves both the collective and individual interests.[43] Anthropologist G. N. Appell criticized those who cited Hardin to "impos[e] their own economic and environmental rationality on other social systems of which they have incomplete understanding and knowledge."[44]

Political scientist Elinor Ostrom, who was awarded 2009's Nobel Memorial Prize in Economic Sciences for her work on the issue, and others revisited Hardin's work in 1999.[45] They found the tragedy of the commons not as prevalent or as difficult to solve as Hardin maintained, since locals have often come up with solutions to the commons problem themselves.[46] For example, it was found that a commons in the Swiss Alps has been run by a collective of farmers there to their mutual and individual benefit since 1517, in spite of the farmers also having access to their own farmland. In general, it is in the interest of the users of a commons to keep them functioning and so complex social schemes are often invented by the users for maintaining them at optimum efficiency.[47][48]

Similarly, geographer Douglas L. Johnson remarks that many nomadic pastoralist societies of Africa and the Middle East in fact "balanced local stocking ratios against seasonal rangeland conditions in ways that were ecologically sound", reflecting a desire for lower risk rather than higher profit; in spite of this, it was often the case that "the nomad was blamed for problems that were not of his own making and were a product of alien forces."[49] Independently finding precedent in the opinions of previous scholars such as Ibn Khaldun as well as common currency in antagonistic cultural attitudes towards non-sedentary peoples,[49] governments and international organizations have made use of Hardin's work to help justify restrictions on land access and the eventual sedentarization of pastoral nomads despite its weak empirical basis. Examining relations between historically nomadic Bedouin Arabs and the Syrian state in the 20th century, Dawn Chatty notes that "Hardin's argument […] was curiously accepted as the fundamental explanation for the degradation of the steppe land" in development schemes for the arid interior of the country, downplaying the larger role of agricultural overexploitation in desertification as it melded with prevailing nationalist ideology which viewed nomads as socially backward and economically harmful.[50]

Elinor Ostrom and her colleagues looked at how real-world communities manage communal resources, such as fisheries, land irrigation systems, and farmlands, and they identified a number of factors conducive to successful resource management. One factor is the resource itself; resources with definable boundaries (e.g., land) can be preserved much more easily. A second factor is resource dependence; there must be a perceptible threat of resource depletion, and it must be difficult to find substitutes. The third is the presence of a community; small and stable populations with a thick social network and social norms promoting conservation do better.[47] A final condition is that there be appropriate community-based rules and procedures in place with built-in incentives for responsible use and punishments for overuse. When the commons is taken over by non-locals, those solutions can no longer be used.[46]

An example of counteracting the tragedy of commons gets possible, if the total amount of common goods is measurable and if there is a majority who sets up the following rules: people have to pay proportionally for their consumption if they report it, but those who refuse to tell, have to pay an equal portion of the amount that is left of the total consumption after subtracting those of all reporting individuals'. Since people will consume mostly diverse amounts, those who - can - consume less, are interested in joining the club of those who report and pay proportionally. This goes on until only the biggest consumer won't be reporting, but they don't have to, as their share can already be calculated by subtracting all the reported values from the total consumption.

Governmental solutions

Governmental solutions may be necessary when the above conditions are not met (such as a community being too big or too unstable to provide a thick social network). Examples of government regulation include privatization, regulation, and internalizing the externalities.

Privatization

One solution for some resources is to convert common good into private property, giving the new owner an incentive to enforce its sustainability. Libertarians and classical liberals cite the tragedy of the commons as an example of what happens when Lockean property rights to homestead resources are prohibited by a government.[51] They argue that the solution to the tragedy of the commons is to allow individuals to take over the property rights of a resource, that is, to privatize it.[52]

Regulation

In a typical example, governmental regulations can limit the amount of a common good that is available for use by any individual. Permit systems for extractive economic activities including mining, fishing, hunting, livestock raising and timber extraction are examples of this approach. Similarly, limits to pollution are examples of governmental intervention on behalf of the commons. This idea is used by the United NationsMoon Treaty, Outer Space Treaty and Law of the Sea Treaty as well as the UNESCOWorld Heritage Convention which involves the international law principle that designates some areas or resources the Common Heritage of Mankind.[53]

In Hardin's essay, he proposed that the solution to the problem of overpopulation must be based on "mutual coercion, mutually agreed upon" and result in "relinquishing the freedom to breed". Hardin discussed this topic further in a 1979 book, Managing the Commons, co-written with John A. Baden.[54] He framed this prescription in terms of needing to restrict the "reproductive right", to safeguard all other rights. Several countries have a variety of population control laws in place.

German historian Joachim Radkau thought Hardin advocates strict management of common goods via increased government involvement or international regulation bodies.[55] An asserted impending "tragedy of the commons" is frequently warned of as a consequence of the adoption of policies which restrict private property and espouse expansion of public property.[56][57]

Internalizing externalities

Privatization works when the person who owns the property (or rights of access to that property) pays the full price of its exploitation. As discussed above negative externalities (negative results, such as air or water pollution, that do not proportionately affect the user of the resource) is often a feature driving the tragedy of the commons. Internalizing the externalities, in other words ensuring that the users of resource pay for all of the consequences of its use, can provide an alternate solution between privatization and regulation. One example is gasoline taxes which are intended to include both the cost of road maintenance and of air pollution. This solution can provide the flexibility of privatization while minimizing the amount of government oversight and overhead that is needed.

The Mid-Way Solution

One of the significant actions areas which can dwell as potential solution is to have co-shared communities that have partial ownership from governmental side and partial ownership from the community. By ownership, here it is referred to planning, sharing, using, benefiting and supervision of the resources which ensure that the power is not held in one or two hands only. Since, involvement of multiple stakeholders is necessary responsibilities can be shared across them based on their abilities and capacities in terms of human resources, infrastructure development ability and legal aspects etc.[citation needed]

Criticism

Radical environmentalist Derrick Jensen claims the tragedy of the commons is used as propaganda for private ownership.[58][pageneeded] He says it has been used by the political right wing to hasten the final enclosure of the "common resources" of third world and indigenous people worldwide, as a part of the Washington Consensus. He argues that in true situations, those who abuse the commons would have been warned to desist and if they failed would have punitive sanctions against them. He says that rather than being called "The Tragedy of the Commons", it should be called "the Tragedy of the Failure of the Commons".[citation needed]

Marxist geographer David Harvey has a similar criticism, noting that "The dispossession of indigenous populations in North America by 'productive' colonists, for instance, was justified because indigenous populations did not produce value", and asks generally: "Why, for instance, do we not focus in Hardin's metaphor on the individual ownership of the cattle rather than on the pasture as a common?"[59]

Hardin's work was also criticised[60][full citation needed] as historically inaccurate in failing to account for the demographic transition, and for failing to distinguish between common property and open access resources.[61] In a similar vein, Carl Dahlman argues that commons were effectively managed to prevent overgrazing.[62] Likewise, Susan Jane Buck Cox argues that the common land example used to argue this economic concept is on very weak historical ground, and misrepresents what she terms was actually the "triumph of the commons": the successful common usage of land for many centuries. She argues that social changes and agricultural innovation, and not the behaviour of the commoners, led to the demise of the commons.[4]

Some authors, like Yochai Benkler, say that with the rise of the Internet and digitalisation, an economics system based on commons becomes possible again. He wrote in his book The Wealth of Networks in 2006 that cheap computing power plus networks enable people to produce valuable products through non-commercial processes of interaction: "as human beings and as social beings, rather than as market actors through the price system". He uses the term networked information economy to refer to a "system of production, distribution, and consumption of information goods characterized by decentralized individual action carried out through widely distributed, nonmarket means that do not depend on market strategies."[63] He also coined the term commons-based peer production for collaborative efforts based on sharing information.[64] Examples of commons-based peer production are free and open source software and open-source hardware.

Comedy of the commons

In certain cases, exploiting a resource more may be a good thing. Carol M. Rose, in a 1986 article, discussed the concept of the "comedy of the commons", where the public property in question exhibits "increasing returns to scale" in usage (hence the phrase, "the more the merrier"), in that the more people use the resource, the higher the benefit to each one. Rose cites as examples commerce and group recreational activities. According to Rose, public resources with the "comedic" characteristic may suffer from under-investment rather than over usage.[65] According to an example explained by Garrett Richards in his article "Comedy of the Commons: Cheerful Options for Shared Resources in an Era of Climate Change" he suggested that climate change issue specifically carbon emissions can be tackled effectively only when the efforts are directly addressing the issues along with the collective efforts from the world economies. His example sheds a light on the fact that if funding is collectively done and solutions are shared across the nations it might help in identifying technologies that can solve the problem of carbon emission issues. Additionally, the more that nations are willing to join up for the cause, collectively work together, and pour in resources, the higher are the chances for successful technological developments.[66]

Related Research Articles

Environmental economics is a sub-field of economics concerned with environmental issues. It has become a widely studied subject due to growing environmental concerns in the twenty-first century. Environmental Economics "...undertakes theoretical or empirical studies of the economic effects of national or local environmental policies around the world .... Particular issues include the costs and benefits of alternative environmental policies to deal with air pollution, water quality, toxic substances, solid waste, and global warming."

In the social sciences, the free-rider problem is a type of market failure that occurs when those who benefit from resources, public goods, or services of a communal nature do not pay for them or under-pay. Free riders are a problem because while not paying for the good, they may continue to access or use it. Thus, the good may be under-produced, overused or degraded.

In economics, a public good is a good that is both non-excludable and non-rivalrous, in that individuals cannot be excluded from use or could benefit from without paying for it, and where use by one individual does not reduce availability to others or the good can be used simultaneously by more than one person. This is in contrast to a common good such as wild fish stocks in the ocean, which is non-excludable but is rivalrous to a certain degree, as if too many fish are harvested, the stocks will be depleted.

Community management or common-pool resource management is the management of a common resource or issue by a community through the collective action of volunteers and stakeholders. The resource managed can be either material or informational. Examples include the management of common grazing and water rights; fisheries and open-source software. In the case of physical resources, community management strategies are frequently employed to avoid the tragedy of the commons and to encourage sustainability.

Collective action refers to action taken together by a group of people whose goal is to enhance their status and achieve a common objective. It is a term that has formulations and theories in many areas of the social sciences including psychology, sociology, anthropology, political science and economics.

Free-market environmentalism argues that the free market, property rights, and tort law provide the best means of preserving the environment, internalizing pollution costs, and conserving resources.

Pastoralism is a form of animal husbandry, historically by nomadic people who moved with their herds. The species involved include various herding livestock, including cattle, camels, goats, yaks, llamas, reindeer, horses and sheep.

John A. Baden is founder and chairman of the Foundation for Research on Economics and the Environment (FREE) based in Bozeman, Montana.

Garrett James Hardin was an American ecologist and proponent of eugenics who warned of the dangers of human overpopulation. He is most famous for his exposition of the tragedy of the commons, in a 1968 paper of the same title in Science, which called attention to "the damage that innocent actions by individuals can inflict on the environment". He is also known for Hardin's First Law of Human Ecology: "We can never do merely one thing. Any intrusion into nature has numerous effects, many of which are unpredictable." He is listed by the Southern Poverty Law Center as a white nationalist, whose publications were "frank in their racism and quasi-fascist ethnonationalism".

The commons is the cultural and natural resources accessible to all members of a society, including natural materials such as air, water, and a habitable earth. These resources are held in common, not owned privately. Commons can also be understood as natural resources that groups of people manage for individual and collective benefit. Characteristically, this involves a variety of informal norms and values employed for a governance mechanism. Commons can be also defined as a social practice of governing a resource not by state or market but by a community of users that self-governs the resource through institutions that it creates.

In economics, a common-pool resource (CPR) is a type of good consisting of a natural or human-made resource system, whose size or characteristics makes it costly, but not impossible, to exclude potential beneficiaries from obtaining benefits from its use. Unlike pure public goods, common pool resources face problems of congestion or overuse, because they are subtractable. A common-pool resource typically consists of a core resource, which defines the stock variable, while providing a limited quantity of extractable fringe units, which defines the flow variable. While the core resource is to be protected or nurtured in order to allow for its continuous exploitation, the fringe units can be harvested or consumed.

Global commons is a term typically used to describe international, supranational, and global resource domains in which common-pool resources are found. Global commons include the earth's shared natural resources, such as the high oceans, the atmosphere and outer space and the Antarctic in particular. Cyberspace may also meet the definition of a global commons.

Elinor Claire "Lin" Ostrom was an American political economist whose work was associated with the New Institutional Economics and the resurgence of political economy. In 2009, she was awarded the Nobel Memorial Prize in Economic Sciences for her "analysis of economic governance, especially the commons", which she shared with Oliver E. Williamson. To date, she remains the first of only two women to win the Nobel Prize in Economics, the other being Esther Duflo.

In psychology, a social trap is a situation in which a group of people act to obtain short-term individual gains, which in the long run leads to a loss for the group as a whole. Examples of social traps include overfishing, energy "brownout" and "blackout" power outages during periods of extreme temperatures, the overgrazing of cattle on the Sahelian Desert, and the destruction of the rainforest by logging interests and agriculture.

A collective action problem or social dilemma is a situation in which all individuals would be better off cooperating but fail to do so because of conflicting interests between individuals that discourage joint action. The collective action problem has been addressed in political philosophy for centuries, but was most clearly established in 1965 in Mancur Olson's The Logic of Collective Action.

The Commonize Costs–Privatize Profits Game is a concept developed by the ecologist Garrett Hardin to describe a "game" widely played in matters of resource allocation. The concept is Hardin's interpretation of the closely related phenomenon known as the tragedy of the commons, and is referred to in political discourse as "privatizing profits and socializing losses."

Common heritage of mankind is a principle of international law that holds that defined territorial areas and elements of humanity's common heritage should be held in trust for future generations and be protected from exploitation by individual nation states or corporations.

Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource. The term applies to natural resources such as: wild medicinal plants, grazing pastures, game animals, fish stocks, forests, and water aquifers.

The double diversion is two-part theory about environmental harm that was developed by William Freudenburg and colleagues beginning in the 1990s, and focusing on "disproportionality" and "distraction." The concept of disproportionality involves the observation that, rather than being a reflection of overall levels of economic activity, the majority of environmental destruction is actually due to a relatively small number of economic actors, which enjoy privileged access to natural resources, “diverting” those resources for the private benefit of the few. Freudenburg's original work on this concept was carried out in conjunction with his colleague from the University of Wisconsin-Madison, Peter Nowak. The reference to the "double" diversion reflects the argument that this first diversion is made possible in large part by the second—the diversion of attention, or distraction, often ironically relying on the widespread but empirically inaccurate belief that environmental harm is economically beneficial to the population as a whole.

The term "knowledge commons" refers to information, data, and content that is collectively owned and managed by a community of users, particularly over the Internet. What distinguishes a knowledge commons from a commons of shared physical resources is that digital resources are non-subtractible; that is, multiple users can access the same digital resources with no effect on their quantity or quality.

↑ United Nations. Dept. of Economic and Social Affairs. Population Division (2004). Levels and trends of contraceptive use as assessed in 2002. United Nations Publications. p.126. ISBN978-92-1-151399-8. some have argued that it may be inferred from the rights to privacy, conscience, health and well-being set forth in various United Nation's conventions […] Parents have a basic human right to determine freely and responsibly the number and spacing of their children (United Nations, 1968)

↑ Frakes, Jennifer (2003). "The Common Heritage of Mankind Principle and Deep Seabed, Outer Space, and Antarctica: Will Developed and Developing Nations Reach a Compromise". Wisconsin International Law Journal. 21 (2): 409–434. HOLwisint21_18.